Ruminants are mammals that are able to acquire nutrients from plant-based food by fermenting it in a specialized stomach prior to digestion, principally through bacterial actions. The process typically requires the fermented ingesta (known as cud) to be regurgitated and chewed again. The process of re-chewing the cud to further break down plant matter and stimulate digestion is called rumination. The rumen forms the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. It serves as the primary site for microbial fermentation of ingested feed. There are about 150 species of ruminants, which include both domestic and wild species. Ruminating mammals include, but are not limited to: cattle, goats, sheep, giraffes, yaks, deer, camels, llamas, antelope, and some macropods.
Sub-acute ruminal acidosis (SARA), also known as chronic or sub-clinical acidosis, is a well-recognized digestive disorder that is an increasing health problem in most dairy herds. Results from field studies indicate a high prevalence of SARA in high-producing dairy herds as producers respond to the demands for increased milk production with higher grain, lower fiber diets that maximize energy intake during early lactation. Dairy herds experiencing SARA will have decreased efficiency of milk production, impaired cow health, and high rates of involuntary culling. The economic cost associated with SARA can be staggering. It is estimated that SARA costs the North American dairy industry between $500 million and $1 billion (USD) annually, with the costs per affected cow estimated at $1.12 (USD) per day. The challenge for dairy farmers and dairy nutritionists is to implement feeding management and husbandry practices that prevent or reduce the incidence of SARA, even in high-producing dairy herds to which higher levels of concentrate are fed to maximize energy intake.
Dietary buffers, such as sodium bicarbonate and sodium sesquicarbonate are commonly added to dairy rations to help manage SARA. Methods of feeding ruminants dietary buffers vary from mineral blocks to supplemented bunk fed total mixed rations (TMR). Research indicates that these buffers increase ruminal pH, and a feeding rate of 0.75% of ration dry matter (DM) is recommended. However, conventional dietary buffers are immediately solubilized in the rumen environment. Although conventional dietary buffers provide a degree of instant neutralization of rumen acid, they are unable to buffer post-meal rumen pH. Accordingly, there is a need in the industry to deliver dietary buffers to ruminants to provide a systematic, longer lasting buffer for acidic rumen conditions.